natural covering - a natural object that covers or envelops; "under a covering of dust"; "the fox was flushed from its cover"scale - a flattened rigid plate forming part of the body covering of many animals shell - the hard largely calcareous covering of a mollusc or a brachiopod test - a hard outer covering as of some amoebas and sea urchins sheath, case - an enveloping structure or covering enclosing an animal or plant organ or part integument - an outer protective covering such as the skin of an animal or a cuticle or seed coat or rind or shell blanket, mantle - anything that covers; "there was a blanket of snow" envelope - a natural covering (as by a fluid); "the spacecraft detected an envelope of gas around the comet" hood, cap - a protective covering that is part of a plant indument, indumentum - a covering of fine hairs (or sometimes scales) as on a leaf or insect roof - the inner top surface of a covered area or hollow space; "the roof of the cave was very high"; "I could see the roof of the bear's mouth" shell - a rigid covering that envelops an object; "the satellite is covered with a smooth shell of ice" skim - a thin layer covering the surface of a liquid; "there was a thin skim of oil on the water" slough - any outer covering that can be shed or cast off (such as the cast-off skin of a snake) snowcap - a covering of snow (as on a mountain peak) vesture - something that covers or cloaks like a garment; "fields in a vesture of green" peridium - outer layer of the spore-bearing organ in many fungi theca, sac - a case or sheath especially a pollen sac or moss capsule indusium - a membrane enclosing and protecting the developing spores especially that covering the sori of a fern bark - tough protective covering of the woody stems and roots of trees and other woody plants |